The 27th Annual LightFair International (LFI) conference was dominated by LED lighting coupled with internet-based control via wireless networks that continues to proliferate in today’s world. The world is increasingly becoming drenched with Internet of Things (IoT) discussions, demonstrations and for some, a certain level of implementation. Electric lighting
transformed our society for over 100 years, boosting our mood and association with the environment, culture, productivity,
and economic conditions. Such enormity pales in comparison to an unprecedented revolution that LFI describes as “Light and Technology in a New Language!”

Dr. Nisa Khan

The LED lighting story started with the drastic lm/W advantage, followed by lm/$ advantage. While both of these factors continued to improve without sacrificing color quality to a significant degree, the lighting industry still remained hesitant. The advantage that really caught on now is making LED lighting intelligent so that it provides the most suitable lighting automatically throughout the day for a variety of circumstances and each LED lamp can make IoT optimal and affordable for every household. The story is amazing!

From the business perspective, this sounds as colossal as it is meant to because light is virtually everybody’s consumable resource; and if this resource comes with energy and cost savings along with enhanced lifestyle as well as health, who could argue against it? However, such painted pictures almost never turn out to be as good as they first appear.

The LED lighting overtaking story has two sides. Most industry participants at LightFair, media included, are touting the great benefits of LED lighting in terms of color tunability, synergy with IoT, higher efficacy, CRI over 95, as well as the freedom to design luminaires to fit various architectural forms that aren’t possible with traditional lamps. These include declarations from Osram representatives that their LED tubular and nostalgic vintage glowing lamps offer a slew of these benefits while offering the exact same light distribution as their fluorescent and incandescent counterparts do; speaker Ms. Cohen (Eaton Lighting) in the seminar on revolution in lighting control systems claimed that the beautiful, tunable LED troffers currently available should not be installed without their light adjustment control units that would offer substantially higher value; Dr. DiLaura (Acuity Brands) explained in "A History of Light and Lighting” seminar that LED lamps now produce light in all different directions just as traditional lamps by placing the tiny individual LEDs in various directions.

LEDs do offer color tunability that covers a broad range of CCT mimicking daylight, much improved CRI, as well as form factors that allow creative architectural lighting. While these are inherent and unique benefits of solid-state lighting, current LEDs have issues not suitable for human-centric lighting and vision developed through evolution. Ms. CJ Brockway, in “The Dangers of Over-lighting”, pointed out some adverse effects of glare and non-uniform illumination for humans, plants, and our ecosystem. LEDs still face wide tunability variabilities due to the persisting binning challenge that require different algorithms to custom-tune CCT for LED luminaires from manufacturers as revealed by Mr. Hamilton from Ketra who further discussed the notable impact of blue-light hazard. We should also assess whether the vast amount of data managed by IoT actually has any significant benefit while compromising personal security. Mr. Charles Knuffke (Wattstopper) and Mr. Shinichi Yamamura (Minebea) pointed out the need for glare reduction and tuning consistency improvements in LED luminaires. These challenges may very well account for why Princeton University is hesitant in replacing their traditional lighting with LED counterparts, experiencing notable objections from many professors against LED upgrades. As presented by Ms. Ziegenbein (Hartranft Lighting), the DOE disclosed that while the LED luminaire shipments account for 46% of all lighting systems in 2015, the total market adoption for LEDs was only 3% in the US. Ms. Goyette of “Lighting Design and Specification” magazine in Canada, supported my stance that not enough people are talking about the LED challenges, clarifying where they come from and what we need to do about them. LED lighting’s mainstream sustainability can only be accomplished by attending to these.

Dr. Nisa Khan

Dr. Nisa Khan is the author of Understanding LED Illumination (CRC Press, 2013). She received her Bachelor's degree in Physics and Mathematics, and her Master’s and Ph.D. degrees in Electrical Engineering. Her 32-year career includes work at Honeywell Solid- State Research Center and AT&T Bell Labs (now Nokia) where she conducted pioneering research on 40-Gb/s optoelectronic and photonic devices. Since 2006 she has been working on LED lamps suitable for general lighting.

Hans
says:
(on May 31, 2016 02:15 PM)

Couldn't agree more: All those digital bells an whistles are for the birds if the light quality still is immature under a variety of aspects: color, flicker, blue-light-hazard, circadian and other bio-optical side effects - and yes, including glare. Solutions are showing up but the industry seems to ignore the impact, trying to sell their old stuff with ever more digital gimmicks, wondering why noone wants to buy the pimped junk.

Nisa Khan
says:
(on May 31, 2016 05:08 PM)

Hello Hans,

I am the author of the article. Thanks for your feedback. You have pointed out the right set of problems for LED lighting and it is also true that there are some solutions that are popping up. The solutions for flicker, glare and spectrum-related problems are difficult and they need to be solved thoroughly and consistently which requires understanding the source of the problems. The general industry is ignoring these problems perhaps because big, quick sales are more attractive or they find the problems simply too difficult to tackle given the timeframe of their interests. But the real challenge could be that there could be an 'Apple' of LED lighting in the works who could just take all businesses away from others - if problems are being ignored. So I encourage the industry to find those who have some solid solutions to flicker, glare, and spectrum-related problems - all of which are linked to semiconductor properties under applied current, temperature increase, and manufacturing constraints.

Hans
says:
(on Jun 01, 2016 07:27 PM)

Hello Nisa,

after my presentation on several identified but still unresolved LED lighting deficiencies during a German lighting congress, two students came up to me. One was a young lady from Russia asking for a copy of my paper as reference in her own diploma work on the subject of LED light glare, who said that she now understood that there is more to it than she thought initially. The second was a young guy from China, who was financing his studiy by selling his father's LED lamps on his German webshop and quoted his father: "My dad keeps telling me that this light is not good." So it seems that some people have a gut feeling that something is wrong with the new light and it is pretty frustrating to see how the mainstream lighting industry is ignoring this and you are right it obviously has to do with a lack of understanding semiconductors as a fundamentally different light source

Nisa Khan
says:
(on Jun 06, 2016 09:52 PM)

Hello Hans,

The feedback from your audience is interesting. Like many other technologies and product types, LED lighting is already suitable for some applications - but not all. Even for those suitable applications, LED lighting can and should be improved; and where they are simply not suitable because of glare, light distribution and spectral challenges, LEDs should not be used as of now until the problems are solved. Surprisingly, most don't even realize there are problems which of course doesn't help them seek for solutions.

Regarding LED glare and light distribution problems, Chapter 6 of my book, "Understanding LED Illumination" would be useful.

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